In the past, unmanned air vehicles (UAVs) mainly supported military and security operations. Now, however, these remotely operated vehicles have additional uses, such as border patrol, disaster relief, traffic reporting, aerial photography, and environmental surveys.
With these additional uses, the UAVs share the National Airspace System (NAS) with commercial aircraft and other manned vehicles. UAV flight operations may be granted by the Federal Aviation Administration (FAA).
When manned aircraft are flying in the National Airspace System, they are required to retain the ability communicate with the FAA at all times. If a manned aircraft loses two-way radio communications, its transponder broadcasts squawk code 7600, which notifies air traffic control (ATC) that communications has been lost, and its pilot follows FAA regulations to safely land the aircraft (see, e.g., 14 CFR 91.185).
UAVs do not have these same capabilities as manned vehicles. If the communications system of a UAV fails, the UAV will be unreachable and, consequently, might enter restricted airspace.
The FAA is concerned about the consequences of UAVs that lose radio communications. The ability to re-establish communications with UAVs is needed.